var base64map = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
let Crypto = {};
var util = Crypto.util = {
  rotl: function (n, b) {
    return (n << b) | (n >>> (32 - b));
  },
  rotr: function (n, b) {
    return (n << (32 - b)) | (n >>> b);
  },
  endian: function (n) {
    if (n.constructor == Number) {
      return util.rotl(n,  8) & 0x00FF00FF |
        util.rotl(n, 24) & 0xFF00FF00;
    }
    for (var i = 0; i < n.length; i++)
      n[i] = util.endian(n[i]);
    return n;
  },
  randomBytes: function (n) {
    for (var bytes = []; n > 0; n--)
      bytes.push(Math.floor(Math.random() * 256));
    return bytes;
  },
  stringToBytes: function (str) {
    var bytes = [];
    for (var i = 0; i < str.length; i++)
      bytes.push(str.charCodeAt(i));
    return bytes;
  },
  bytesToString: function (bytes) {
    var str = [];
    for (var i = 0; i < bytes.length; i++)
      str.push(String.fromCharCode(bytes[i]));
    return str.join("");
  },
  stringToWords: function (str) {
    var words = [];
    for (var c = 0, b = 0; c < str.length; c++, b += 8)
      words[b >>> 5] |= str.charCodeAt(c) << (24 - b % 32);
    return words;
  },
  bytesToWords: function (bytes) {
    var words = [];
    for (var i = 0, b = 0; i < bytes.length; i++, b += 8)
      words[b >>> 5] |= bytes[i] << (24 - b % 32);
    return words;
  },
  wordsToBytes: function (words) {
    var bytes = [];
    for (var b = 0; b < words.length * 32; b += 8)
      bytes.push((words[b >>> 5] >>> (24 - b % 32)) & 0xFF);
    return bytes;
  },
  bytesToHex: function (bytes) {
    var hex = [];
    for (var i = 0; i < bytes.length; i++) {
      hex.push((bytes[i] >>> 4).toString(16));
      hex.push((bytes[i] & 0xF).toString(16));
    }
    return hex.join("");
  },
  hexToBytes: function (hex) {
    var bytes = [];
    for (var c = 0; c < hex.length; c += 2)
      bytes.push(parseInt(hex.substr(c, 2), 16));
    return bytes;
  },
  bytesToBase64: function (bytes) {
    if (typeof btoa == "function") return btoa(util.bytesToString(bytes));
    var base64 = [],
      overflow;
    for (var i = 0; i < bytes.length; i++) {
      switch (i % 3) {
        case 0:
          base64.push(base64map.charAt(bytes[i] >>> 2));
          overflow = (bytes[i] & 0x3) << 4;
          break;
        case 1:
          base64.push(base64map.charAt(overflow | (bytes[i] >>> 4)));
          overflow = (bytes[i] & 0xF) << 2;
          break;
        case 2:
          base64.push(base64map.charAt(overflow | (bytes[i] >>> 6)));
          base64.push(base64map.charAt(bytes[i] & 0x3F));
          overflow = -1;
      }
    }
    if (overflow != undefined && overflow != -1)
      base64.push(base64map.charAt(overflow));
    while (base64.length % 4 != 0) base64.push("=");
    return base64.join("");
  },
  base64ToBytes: function (base64) {
    if (typeof atob == "function") return util.stringToBytes(atob(base64));
    base64 = base64.replace(/[^A-Z0-9+\/]/ig, "");
    var bytes = [];
    for (var i = 0; i < base64.length; i++) {
      switch (i % 4) {
        case 1:
          bytes.push((base64map.indexOf(base64.charAt(i - 1)) << 2) |
            (base64map.indexOf(base64.charAt(i)) >>> 4));
          break;
        case 2:
          bytes.push(((base64map.indexOf(base64.charAt(i - 1)) & 0xF) << 4) |
            (base64map.indexOf(base64.charAt(i)) >>> 2));
          break;
        case 3:
          bytes.push(((base64map.indexOf(base64.charAt(i - 1)) & 0x3) << 6) |
            (base64map.indexOf(base64.charAt(i))));
          break;
      }
    }
    return bytes;
  }
};
Crypto.mode = {};
export default Crypto;
